channels_forum_create_thread

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate non-read-only, non-idempotent, non-destructive behavior. The description adds useful behavioral constraints beyond annotations: the nested message requirement, the content/embed/component condition, and the 'Plain text channels - Discord rejects' caveat. It does not contradict annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured with bolded section labels, concise bullet points, and no filler. Every sentence contributes actionable information, keeping the length appropriate for the tool's complexity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with 7 parameters and a nested message object, the description covers purpose, when/when-not, body shape requirements, and return shape. It provides sufficient context for an agent to select and invoke the tool correctly, complementing the rich schema and output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is high (86%), and the schema already documents the key parameters including message's requirement for content/embeds/components. The description reinforces the nested body shape but does not add significant meaning beyond what the schema provides. Some parameters like rate_limit_per_user lack detail, but the description does not compensate for that.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb-object statement: 'Create a new forum (or media) thread with an initial message in one request.' This clearly identifies the tool's unique scope and differentiates it from the sibling messages_create_thread by explicitly calling out the alternative.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit 'When to use' and 'When NOT to use' sections. It names the alternative tool (messages_create_thread) for anchored threads and states that plain text channels are rejected, giving an agent clear decision criteria.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.